Micrometer caliper



Sept. 15, 1925.

1,553,875 J. w. PARKER mcnoma'rma CALIPER Filed June 20. 1924 attmuu;

Patented Sept. 15, 1925.

NIT -ST j E PATENT OFFICE.

. JOHN w. rnaxmorssnaame'ron, nrronn ISLAND, ASSIGNOR T BROWN & SHARPE MANUFACTURING. COMPANY. OF PROVIDENCE, RHODE ISLAND.

MICROMETER' CALIPER.

. v Application filed June 20, 1924. Serial No. 721,336.

To all 'wlwm'it may concern: I 7

Be it known that'I, JOHN W. PARKER, a citizen of the United States, residing at Barrington, in, the county State of Rhode Island, have invented new and useful Improvements in Micrometer Calipers, of which the following is a specification; F

I This invention relates to certain new and useful Improvements in micrometer calipers and pertains more particularly to a ratchet for enabling sensitive control of the feed of the micrometer screw so as to insure absolute accuracy of measurement.

Theprimary object of the invention is to provide a ratchet structure of maximum simplicity involving a minimum of parts which can be easily and quickly applied to the micrometer screw so as to reduce the cost of production to a relatively marked degree.

A further object of the invention is to pro,- vide a ratchet structure which is extremely sensitive so as to freely idle upon a certain degree of pressure being exceeded, and which at the same time is not likely to get out of order. V I

The invention further aims to provide a ratchet structure which requires no modificationv of the micrometer barrel in being applied to the micrometer screw.

The invention has still further and other objects which will be later set forth and manifested in the course of the following description.

In the drawings Figure 1 isa side elevation of tion applied to calipers;

Figure 2, is an enlarged side elevation partly in sectionof the invention detached from the calipers, and

Figure 3 is a section on line 3-3 of Figure 2.

In proceeding in accordance with the presthe invenent invention a cylindricalbody 1 is employed, which is formed with an attaching shank 2 at its inner end, the latter being received in an opening provided therefor in the outer end of the micrometer screw 3, a driving or frictional fit being provided to secure the'shank to the screw. The outer end of the body 1 is formed with a rim 4 providing a cup-like part. The body'is formed with an axial screw threaded hole 5 extending through its outer end and in which is received a screw 6 shouldered at 7 of Barrington and V and having a head 8 on its outer end. The ratchet includes a sleeve-like member indicated at 9 which has a knurled periphery.

The ratchet sleeve is received over the screw 6 and has a counterbored part 10 in which the head 8 of the screw is received, and at its inner end is formed with radially extending ratchet teeth 11. The pawl is formed of a piece of spring wire or other suitable material and has an inner coil or eye 12 atone end and has its other end curved at 13, the end edge 14; of the curved part 13 being formed to engage the ratchet teeth 11. The coil or eye 12 of the sprin pawl snugly engages about the reduce threaded end of the fastening screw 6 and is abutted or held by and between the outer end wall of the body 1 and the shoulder 7 of the screw 6 so as to be rigidly clamped against movement. The curved arm 13 is ofi' set with relation to the wall 15 of the body so as to have free movement toward and away from the wall as the ratchet teeth 11 move over the pawl. The coil or eye 12 further serves to properly or suificiently space the wall and ratchet to permit of the aforementioned free movement of the curved the attachment may be applied by merel boring a hole to receive thestud or shan 2, in the end of the micrometer screw.

The device extends outwardly from an end of the micrometer screw and in no way interferes with or affects the barrel of the Having thus described my invention, what I claim as new and desire to secure by Let: ters Patent is 1. In combination with the screw of a 'micrometer caliper having a hole in the end thereof, an attachment including a body having a stud on one end received in said hole and having a cup-like part on its opposite end, said body having ascrew hole extending through its outer end, a screw in said threaded hole having a shoulder, a knurled sleeve on the second screw having ratchet teeth on its inner end, and having said innerend extending into the cup-like part, and a spring wire pawl having an eye on one end receivedover the second screw and clamped between the shoulder and the outer end wall of the body the pawl having a curved free end part the end edge t e ody-t0 h s r ei y Amine a cup shaped outer end, ,a screw secured to the body and having a shoulder thereon, a sleeve on the on one end extending spring pawl impinged at one --end' between the bottom wall of the cup and the shoulder andhaving its opposite end ireeandformed to engagethe ratchet teeth.

3. In combination with the screw of a micrometer caliper, a'body, means to connect thebody to the screw, a spring pawl having one end thereof engaged with a part of the body, Par nga a screw having a shouldered screw having ratchet teeth into the cup, and a with said end of the pawl to clamp same against said ,partof the body, and a rotatable member on the second screw havi g ratchet teeth, the other end of the pawl beingiree and offset and formed to engage the ratchet teeth.

4. In combination wlth the screw of a micrometer caliper, a body, means to connect the body to the screw, a spring pawl havingoneendmhereof engaged with a part of the body, means to clamp said endoi' the spring pawl against said part of the body, anda rotatable device on said last named means lrarin'g ratchet teeth, the other end of the pawlbeing ztree andiormed to JOHN w. PARKER. 

